By STACY LIBERATORE, US SCIENCE & TECHNOLOGY EDITOR
Published: 16:03 BST, 14 August 2026 | Updated: 16:47 BST, 14 August 2026
Biologists are sounding the alarm over two growing threats on a potentially dangerous collision course with the US.
Researchers warned that vampire bats moving north could combine with chronic wasting disease (CWD), a fatal, contagious neurological illness spreading south through deer populations, potentially creating a pathway for a mad cow-like disease to reach humans.
Like mad cow disease, the incurable condition would be caused by abnormal proteins that destroy the brain, triggering behavioral changes, loss of coordination and eventually death.
The feared chain of transmission would begin when a vampire bat feeds on a deer infected with CWD and ingests the malformed proteins, known as prions, in its blood.
The bat could then expose cattle to those prions when it feeds again.
Researchers fear repeated exposure could eventually allow a strain of the disease to breach the species barrier and cause a fatal illness in cattle resembling mad cow disease.
Humans could then potentially become infected by eating contaminated beef, developing a deadly neurological condition.
Peter Larsen, an associate professor at the University of Minnesota, said: ‘I don’t know why more people aren’t paying attention to this, because it gets scary really fast.’
Like mad cow disease, the incurable condition would be caused by abnormal proteins that destroy the brain, triggering behavioral changes, loss of coordination and eventually death
However, there is currently no evidence that vampire bats transmit CWD, that cattle have contracted the deer disease or that it has infected humans.
Vampire bats are nocturnal mammals native to Central and South America that survive exclusively on blood.
Although they have not established populations in the US, warming temperatures are allowing them to expand northward through Mexico and closer to states where CWD is already present.
The fatal deer disease has now been detected in 37 states, and Larsen said forecasts indicate it could circulate across all of the lower 48 states, every Canadian province and Mexico by 2030.
